Pinpoint Test C: DTC B1484 - Brake Pedal Input Open Circuit

WARNING: This page is about a different car, the 2005 Mercury Sable and 2005 Ford Taurus. However, it is still accessible from the selected car via links, so may be relevant.

C1 CHECK THE STOPLAMPS
- Press the brake pedal while checking the stoplamps.
- Do the stoplamps illuminate?
- Yes : GO to C2.
- No : REFER to EXTERIOR LIGHTING to further diagnose the stoplamps.
C2 CHECK CIRCUIT 810 (RD/LG) FOR AN OPEN
- Key in OFF position.
- Disconnect: ABS Module C135.
- Measure the voltage between the ABS module connector C135 pin 6, circuit 810 (RD/LG), harness side and ground while applying and releasing the brake pedal.
  
  Fig 1: Measuring Voltage Between ABS Module Connector C135 Pin 6, Circuit 810 (RD/LG), Harness Side And Ground
  Courtesy of FORD MOTOR CO.
- Is the voltage greater than 10 volts with the brake pedal applied, and zero volts with the brake pedal released?
- Yes : GO to C3
- No : REPAIR the circuit. CLEAR the DTCs. TURN the ignition switch from OFF to ON. REPEAT the ABS self-test. If any DTCs are retrieved, REFER to the ANTI-LOCK BRAKE SYSTEM (ABS) MODULE DIAGNOSTIC TROUBLE CODE (DTC) INDEX . If no DTCs are retrieved, CARRY OUT a drive test above 15 km/h (9 mph), then REFER to the SYMPTOM CHART .
C3 CHECK FOR CORRECT ABS MODULE OPERATION
- Disconnect all ABS connectors.
- Check for:
  - corrosion
  - pushed-out pins
- Connect all ABS connectors and make sure they seat correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?
- Yes : INSTALL a new ABS module. REFER to ANTI-LOCK BRAKE SYSTEM (ABS) MODULE . TEST the system for normal operation.
- No : The system is operating correctly at this time. Concern may have been caused by a loose or corroded connector. CLEAR the DTCs. TURN the ignition switch from OFF to ON. REPEAT the ABS self-test. If any DTCs are retrieved, REFER to the ANTI-LOCK BRAKE SYSTEM (ABS) MODULE DIAGNOSTIC TROUBLE CODE (DTC) INDEX . If no DTCs are retrieved, CARRY OUT a drive test above 15 km/h (9 mph), then REFER to the SYMPTOM CHART .